1 Introduction

In the LD converter process, pure oxygen is blown on a molten iron bath for refining purposes. Elements dissolved in the molten iron, e.g. C, Si, Mn, P, etc., but also part of the molten iron, are oxidised. They either form a slag phase covering the hot metal or, in the case of C, gas bubbles containing CO and CO ₂. Several reaction zones can be identified in Figure 1. In the hot spot, the oxygen directly reacts with iron and dissolved elements. Due to the impact of the oxygen jet, iron droplets are dispersed in the slag phase as well as slag droplets in the metal bath. The metal-slag dispersion is mixed further by CO and CO ₂ bubbles and serves as the main reaction zone. A third zone contains the hot metal that is not dispersed in the slag, but forms the bath underneath. Droplets from the dispersion fall back into this bath.

Figure 1: LD converter process

2 Process Model Development

The task of developing a suitable converter model will be discussed based on the decarburisation reaction of the iron melt. Obviously, the rate of the decarburisation reaction depends on the reaction rate of

and the transport conditions in the converter. Thereby, these are determined by oxygen blowing conditions and CO formation. On the other hand, CO formation is influenced by the decarburisation reactions.

Intermediary formation of FeO in the hot...